The answer is no. Iron is placed higher than copper, so NO REACTION WILL OCCUR.

3. Balance the equation.

3Cu + Fe(OH)3--> Fe + 3CuOH

YAY. We're done!!

**Some things to remember:
Whatever element that is replacing the original element has to be higher than the original, or else a reaction will NOT occur.
If the replacement element is higher, rest assured. A reaction will occur.

KEEP YOUR ACTIVITY SERIES HANDY!!

Time for a song that is really educational. I mean, look at the title!!

Tuesday, January 25, 2011

-the chemicals that are reacting together
-the number of particles involved
-the type of particles involved (ie. atoms, ions, molecules)
-the number of moles per substance
-the reactants & the products
-the state of the substance (ie. solid, liquid, gas, or aqueous)

To balance the right side of the equation, there needs to be 2 chloride atoms.

Na + Cl2 --> 2NaCl

Count the atoms again:

right: left:
Na - 2 Na - 1
Cl - 2 Cl - 2

Now add 2 in front of the sodium metal; therefore, the balance equation is:

2Na + 1Cl2 --> 2NaCl

And the coefficients cannot be reduced!

What are diatomics?

The diatomics are 7 special non-metals that always form a molecule of 2 when alone. They are:

Hydrogen, oxygen, fluoride, bromide, iodide, nitrogen, chloride

The diatomics are in gas form & are expressed as H2, O2, F2, Br2, I2, N2, & Cl2 in word equations.

~~Here is a trick to remember the diatomics~~

HOFBrINCl ("Hoffbrinkle")

or

I Bring Clay For Our New House

and they form a "7" shape in the periodic table! :D

another note: When sulphur & phosphorous are by itself, it is expressed as

S8 and P4

Some tips for balancing equations:
-treat chemicals that come in groups (NO3, PO4) like a whole (make sure to balance these first!)
-balance everything else before balancing H and O
**remember, the coefficients have to be a whole number!!

Friday, January 14, 2011

Review: Recall that Avogadro's Hypothesis states that at the same pressure & temperature, equal volumes of different gases have the same number of particles.
Also, gases will change volume (contract or expand) with changes in pressure in temperature

So what is molar volume??!
The molar volume of a gas is the volume occupied by 1 mole of gas at Standard Temperature & Pressure (STP), which is 0 degrees Celsius and 1 atmosphere of pressure.

ANY gas at STP has a volume of 22.4 litres.
Therefore, the converstion factor is mol/22.4L or 22.4L/mol

So, chemists and chemistry students like yourself need to learn how to dilute these concentrated substances.
But before you learn how to do that, burn this concept into your mind:

MOLES OF SOLUTE IS CONSTANT

ie. moles in the solute before=moles in the solute after dilution

Formula to help you better understand it: M1L1=M2L2

Let's break down a question:
Concentrated HCl is 55.6mole/L. How can we make 250 mL of 0.500 mole/L HCl?
1. Write down the formula.
M1L1=M2L2
2. Plus in the numbers.
(55.6M)(L1)=(0.500M)(0.250L)
3. Solve for L1.
(55.6M)(L1)=(0.500M)(0.250L)55.6L1=0.125
55.6 55.6
L1=0.002248L
4. Put answers to the appropriate number of sig. figs.
L1=2.25mL
5. Don't forget to include UNITS!!

More Practice Problems:
1. 150.0mL of 0.025M KOH solution is added to 150.0mL of water. Calculate the new molarity.

2. A 0.225M solution is concentrated by evaporation to reduce the final volume of 75.0mL and a molarity of 0.275M. Calculate the original volume.

Wednesday, January 5, 2011

Molarity

Molarity is the number of moles of the substance contained in 1 Liter of solution. This is based on a substance in a solution. Also the other name for Molarity is called Molar Concentration.

There is a difference between concentration, concentrated, and dilute. The concentration of a substance in a solution is the quantity of the substance, which is in a given volume of the solution. The concentrated solution has a high concentration. This means that a lot of the substance is dissolved in the solution. Dilute solution has a low concentration which means that very little of the substance is dissolved.

Here is the Formula:

Molarity/ Molar Concentration = moles

Volume

Or this way might be easier to remember:

M = mol

L

That means if you want to solve for L it would be:

L = mol

M

That means if you want to solve for mol it would be:

Mol = M X L

Here is an example:

If 3.0 L of solution contain 5.0 mol of CaCl, what is the molarity of the CaCl?

Molarity = 5.0 mol = 1.666666667

3.0 L

= 1.6 mol

L

Let’s try something harder now! ~

This time you have to convert mL into Liters for the equation to work!